Differential Diagnosis for the Rash
- Single most likely diagnosis
- Eczema (Atopic Dermatitis): This is often the first consideration for a rash, given its high prevalence and the fact that it can appear anywhere on the body. It's characterized by itchy, inflamed skin, and can be acute or chronic.
- Other Likely diagnoses
- Contact Dermatitis: This condition occurs when the skin comes into contact with an irritant or allergen, causing a reaction. It's common and can present similarly to eczema but is typically more localized.
- Psoriasis: An autoimmune condition that speeds up the life cycle of skin cells, causing cells to build up rapidly on the surface of the skin. The extra skin cells form scales and red patches that itch or burn.
- Allergic Reaction: Could be due to a variety of causes including drugs, foods, or environmental factors. Symptoms can range from mild to severe and include hives, itching, and swelling.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Meningococcemia: A severe infection that can cause a rash, among other symptoms. It's critical to identify quickly due to its high mortality rate if not treated promptly.
- Rocky Mountain Spotted Fever (RMSF): A bacterial infection spread by ticks, characterized by fever, headache, and a distinctive rash. Early treatment is crucial to prevent serious complications.
- Toxic Epidermal Necrolysis (TEN) or Stevens-Johnson Syndrome (SJS): Severe skin and mucous membrane disorders usually caused by medications. They are medical emergencies and can be fatal if not recognized and treated promptly.
- Rare diagnoses
- Pemphigus: A group of rare skin disorders that cause blistering of the skin and mucous membranes. It's an autoimmune disease that can be life-threatening if not treated.
- Dermatomyositis: An inflammatory disease characterized by skin rash and muscle weakness. It's a rare condition that can be associated with underlying malignancies.
- Erythema Multiforme: An immune-mediated disorder characterized by target-like lesions on the skin. It can be triggered by infections or medications and, while usually self-limiting, can have severe forms.